As an outdoor leisure product, sunshade umbrellas are widely used in squares, parks, on the beaches, patio and other leisure places, offering comfortable shade to shield people from the sun.
Conventional umbrellas generally have a main pole extending from the center of the umbrella downward to a support surface. An improvement on this design is the offset umbrella, shown for example in U.S. Pat. No. 5,937,882. The main pole of an offset umbrella utilizes a cantilever arrangement to suspend the canopy to the side of the main pole such that the main pole does not occupy space in the shady area beneath the canopy. For additional convenience, the angle of the canopy can be adjusted with respect to the main pole.
Existing adjustable offset umbrellas such as that disclosed in the previously mentioned U.S. Pat. No. 5,937,882 utilize a crank mechanism both for raising and lowering the canopy and for adjusting the angle of the canopy. The crank mechanism is mounted to the main pole, and the rope moves along a complex path with many turning points. This arrangement requires more winding force, and the rope can easy bind and wear, adversely affecting the umbrella's operation. These disadvantages make the operation of the umbrella burdensome and decrease the enjoyment of leisure time.